The present disclosure relates generally to vehicle Onboard Diagnostic (OBD) systems and, more particularly, to a method and system for analyzing OBD data in accordance with a vehicle inspection and maintenance program.
The Clean Air Act as amended in 1990 (CAA) requires the Environmental Protection Agency (EPA) to set guidelines for states to follow in designing and running vehicle inspection and maintenance (I/M) programs. As well as distinguishing between basic and enhanced I/M programs, these guidelines must clarify how states are to meet other minimum design requirements set by the CAA. One such requirement that applies to both basic and enhanced I/M programs is the performance of Onboard Diagnostic (OBD) system checks as part of a required, periodic vehicle inspection.
Typically, states utilize computer systems in various implementations to direct and assist inspectors in performing safety and emissions inspections. Currently, states perform the emissions inspection of motor vehicles by analyzing the exhaust of the vehicle under simulated driving conditions. Since 1996, however, both foreign and domestic motor vehicles have been provided with an Onboard Diagnostics (OBD) capability. An OBD system is a system of vehicle component and condition monitors controlled by a central, onboard computer. The OBD computer uses software designed to signal the motorist when conditions exist that could lead to a vehicle""s exceeding its emission standards by 1.5 times the standard. Accordingly, as part of an overall vehicle inspection and maintenance (I/M) program under the Clean Air Act, each state will now be required to incorporate a check of a vehicle""s OBD computer as part of these programs to perform the emissions inspection.
An OBD-I/M check generally includes two types of examination. First, an inspector performs a visual check of the dashboard display function and status (also referred to as the malfunction indicator light xe2x80x9cMILxe2x80x9d and/or bulb check). A second procedure is an electronic examination and analysis of the OBD computer itself. Generally speaking, a scan tool or similar hand-held instrument is used to extract emissions data from the vehicle OBD computer in the form of standardized Diagnostic Trouble Codes (DTCs).
Due to the relative newness of standardized OBD systems (also referred to as On-Board Diagnostics Generation II or OBD II), certain difficulties have arisen. For example, certain vehicle models are not currently compatible with OBD software from the standpoint of xe2x80x9creadinessxe2x80x9d. Readiness refers to whether or not the vehicle""s computer has had the opportunity to fully monitor and evaluate the vehicle""s performance. Thus, the OBD stores a status flag or xe2x80x9creadiness codexe2x80x9d for each monitor. The readiness code is different from a DTC in that the readiness code does not indicate a vehicle fault, but rather whether or not a given monitor has been run (i.e., whether or not the component or system in question has been checked to determine if it is functioning properly). In some vehicles, the readiness codes may be cleared at key off. In other vehicles, a xe2x80x9ctrip basedxe2x80x9d design may cause catalyst and evaporative monitors to reflect a xe2x80x9cnot readyxe2x80x9d state. In either case, such scanning anomalies are not taken into account by existing OBD scanning systems.
Another difficulty encountered with OBD-I/M programs is in locating the Data Link Connector (DLC) for certain vehicles. The DLC is the interface between a vehicle""s OBD computer and the OBD scanner. Connecting an OBD scanner to the DLC allows I/M inspectors and vehicle repair technicians to read the readiness status of the vehicle""s various onboard monitors as well as any DTCs. Although the DLC is usually located under the dashboard on the driver""s side of a vehicle, this is not always the case. While the EPA has compiled a listing of vehicles with hard-to-find DLC locations by make and model year, such information may not be readily or conveniently accessible by the inspector.
The above discussed and other drawbacks and deficiencies of the prior art are overcome or alleviated by a method for on-board diagnostics testing of a vehicle under inspection. In an exemplary embodiment, the method includes configuring a user interface in communication with a software system, and configuring a communications link in communication with the software system. The software system is capable of communicating with an on-board vehicle computer system. In addition, an analysis and reporting module is configured in communication with said software system, wherein the software system manages the user interface, the communications link, and the analysis and reporting module in a manner guiding an inspector through an inspection of the vehicle. An inspection of the vehicle includes an analysis of the on-board vehicle computer system.
In one embodiment, the method further includes receiving inputted vehicle data fields for the vehicle under inspection, comparing the inputted vehicle data fields to data contained in a vehicle lookup table, and determining whether the vehicle under inspection is subject to on-board diagnostics testing. If the vehicle under inspection is subject to on-board diagnostics testing, then the software system guides an inspector through a vehicle inspection process.
In a further aspect, if the vehicle under inspection is subject to on-board diagnostic testing, then based upon the inputted vehicle data fields and the data contained in the vehicle lookup table, it is determined whether the vehicle under inspection is subject to a standardized test procedure or a specialized test procedure corresponding to the vehicle under inspection. If it is determined that the vehicle under inspection is subject to a specialized test procedure, then the software system guides the inspector through the specialized test procedure.
In yet a further aspect, the method includes directing the inspector to locate an on-board diagnostic connector in the vehicle under inspection, wherein information on the location of the on-board diagnostic connector is also included in the vehicle lookup table. Furthermore, communication between the analysis and reporting module and the on-board vehicle computer system is established. Then, the operational status of a malfunction indicator light (MIL) included within said vehicle under inspection is verified. It is then determined whether the MIL has been commanded on during the operation of the vehicle under inspection, and vehicle diagnostic trouble codes are retrieved and stored.
In still a further aspect, a readiness status is determined for each of a set of vehicle parameter monitors, the readiness status indicative of whether a given vehicle parameter monitor has had sufficient time to monitor the parameter associated therewith. A possible readiness status for each vehicle parameter monitor includes one of: completed, not completed, and not enabled. The set of vehicle parameter monitors includes at least one of: a misfire, a fuel system, a comprehensive component, a catalyst, a heated catalyst, an evaporative system, a secondary air system, an air conditioning system, an oxygen sensor, an oxygen sensor heater, and an exhaust gas recirculation system monitor.